Field of the Invention
The present invention relates to a method of producing 2-hydroxy-1,4-naphthoquinone. Specifically, the invention relates to a method of producing 2-hydroxy-1,4-naphthoquinone, which is useful as, for example, a raw material for producing a resin, an intermediate of a face wash, or an intermediate of a pharmaceutical or agricultural chemical, in a high yield and a high purity.
Background Technology
As a method of producing 2-hydroxy-1,4-naphthoquinone using 2-hydroxynaphthalene (or 2-naphthol) as a raw material, there is disclosed a method of oxidizing 2-hydroxynaphthalene with gaseous oxygen in methanol in the presence of a cobalt catalyst and a caustic alkali. However, in this method, an expensive catalyst, such as a cobalt morpholine catalyst fixed to a polymer, must be used. In addition, the yield is insufficient. This method is described in the following non-patent document 1.
As a method of producing 2-hydroxy-1,4-naphthoquinone using 1-hydroxynaphthalene as a raw material, there is disclosed a method of oxidizing 1-hydroxynaphthalene with hydrogen peroxide in an aqueous potassium hydroxide solution in the presence of a vanadium catalyst. However, in this method, 1-naphthol used as a raw material is expensive, and also the yield is low. Thus, there is a problem of cost. This method is described in the following non-patent document 2.